There comes a point where obsessing over the latest set of wheels, aero suit, helmet, or even water bottle placement can be an exercise in futility. I’m not saying it isn’t important, but it should always be secondary…..
The real issue at hand when you approach a race is your bike fitness, plain and simple(combined with run and swim fitness too). If you lack fitness on the bike, then no amount of equipment (aside from the obvious well functioning bike) will snatch you out of the depths of mediocrity. Your fitness is what you have 100% control over so take the time to build “the rider” and don’t over think your set up. After you know your bike fitness is dialed in, then I would start thinking about the remaining 1%.